“data up” – frameworks that map the form data from domain bean definition(i.e struts) . The data is collected in regard to the bean definition. There is no business logic based on the User Interface in this model. Moreover, the UI is passive, and the logic is on the server side.

“bottom down” – the “data up” does not work well for GWT, since most of the logic moves to the client, and the server side is just a thin DAO wrapper. Pectin works with the domain bean without being constrained by it.